Commutator-brush and holder for dynamo-electric machines and motors



(No Model.)

P. J. SPRAGUE. I GOMMUTATOB. BRUSH AND HOLDER FOR DYNAMO ELECTRIC MACHINES AND MOTORS.

No. 466,448. Patented Jan. 5, 1892.

UNITED STATES PATENT OFFICE.

FRANK J. SPRAGUE, OF NEW YORK, N. Y., ASSIGNOR TO THE EDISON GENERAL ELECTRIC COMPANY, OF NEV YORK.

COMMUTATOR-BRUSH AND HOLDER FOR DYNAMO-ELECTRIC MACHINES AND MOTORS.

SPECIFICATION forming part of Letters Patent No. 466,448, dated January 5, 1892.

Application filed December 10, 1886- Serial No. 221,175. (No model.)

To all whom it may concern.-

Be it known that I, FRANK J SPRAGUE, of New York city, in the county and State of New York, have invented certain new and useful Improvements in D ynamo-Electric Machines, (Oase MM,) of which the following is a specification.

My invention relates to the commutatorbrushes and holders therefor, in dynamo-electric machines and electro-dynamic motors,

my principal object being to so arrange the brushes that the armature 'may run readily in either direction, and also to produce a simple and efficient construction for the brushes and brush-holders.

My invention consists in the novel devices and combinations of devices employed by me in accomplishing the above-named objects, as hereinafter set forth and claimed.

My invention is illustrated in the accompanying drawings, in which Figure 1 is a view in elevation of a brushholder embodying my invention, with a portion of the commutator-cylinder; and Fig. 2 an end view of the same.

Only one side of the commutator and one set of brushes are shown.- The other set of brushes is constructed and arranged in precisely the same way.

Each brush-holder is carried by an arm A, extending from a collar B, sleeved upon the armature-shaft or upon the journal-box. At the outer end of arm A is formed a collar and held in this collar is a spindle D, separated from the metal arm by the insulatingsleeve E, which has a flange E. From the spindle extends the brush-carrying box or frame F, and the whole is secured together by insulating-washer G, metal washer G, and nuts H on the screw-threaded end of the cylinder.

The frame F, as shown, supports two commutator-brushes. One or any larger number of brushes may be so carried on each side of the commutator-cylinder, according to the size of the machine and the current to be collected or conveyed. Since the two brushes shown are in all respects alike, Iwill describe one of them in detail.

Through apertures in the frame]? pass two rods I I, which are bridged outside of the frame by a metal plate K and secured by nuts 0. a, placed upon their screw-threaded ends. Midway between the rods 11 an aperture extends through the frame, which is enteredby a rod or spindle M, extending up some distance above the bridge plate K, passing through a collar 19, resting on the bridge-plate and terminating in a milled head 0 for turning the spindle. Upon the spindle M, between the collar b and the head 0, is coiled a spiral spring N. The lower ends d d of rods I I are enlarged and are joined by a cylindrical pin 6, passing through apertures in these enlarged ends. The brush is inserted and held in a metal head 0, having a curved back P and shoulders f f. The pin e passes loosely through the back P, forming a pivot on which the brush may rock in either direction. 7

The brush itself consists of a number of thin flat metal strips Q, placed together and having a number of slits g g, extending back to near the back of the brush. The end of the brush has opposite bevels at h h, and I prefer to form in it also a slot 1 in the direction of its width,which gives flexibility in the direction of revolution of the co mmutatorcylinder.

R is the commutator-cylinder, made up, as usual,0f a number of metal bars separated by insulation. The brushes bear upon the cylinder in the manner shown most clearly in Fig. 2. It will be seen that it is an end-on brush-that is, one placed perpendicular to the cylinder, as distinguished from the usual form, in which the planes of the brushes are at an angle to the plane of the axis of the cylinder; but being pivotedit is able to rock in the direction in which the commutator revolves, and when the direction of revolution is changed the brush rocks over accordingly, resting on its opposite bevel. The brush or brushes on the opposite side of the commutator are, as stated, arranged in the same manner and also rock over in the direction of revolution.

By means of the set-screws Z Z, passing through the enlarged ends (1 d and setting against the shoulders ff, the extent of movement of the brushes may be limited and adjusted.

When the machine is started, the brushes are forced back against the spiral springs a suitable distance, as shown, and therefore as the ends wear the brushes are continually fed forward by the springs in a direction perpendicular to the coin nlutator-cylinder and practically without increasing the angle of displacement. The tension of the springs is adjusted and regulated by turning the spindles K in or out of the frame F, and to assist in maintaining them at the right tension the setscrews m m, setting against the spindles, may be provided.

To make an electrical connection other than that of the sliding rods, a flat spring 0 or other flexible connection may extend between the frame F and the enlarged ends of the rods.

My invention is especially adapted for use with electro-dynamic motors which are required to run in either direction, since the brushes immediately adapt themselves to the changes in direction, while maintaining substantially the same positions upon the cylinder.

The brushes may be readily removed from contact with the cylinder by loosening the nuts upon the end of spindle D.

\Vhat I claim is- 1. The combination, with a commutatorcylinder, of an end-on commutator-brush having its end beveled in two directions, substantially as set forth.

2. The combination, with a commutatorcylinder, of an end-on commutator-brush having its end beveled in two directions and adapted to rock on either side of a center, substantially as set forth.

3. The combination, with the stationary brush-holding frame, of the rods passing through said frame-and the brush carried by said rods and bearing on the commutator-cylinder perpendicular thereto, substantially as set forth.

4. The combination, with the stationary brush-holding frame, of the rods passing through the same and the end-on brush pivoted upon said rods, substantially as set forth.

5. The combination, with the stationary brush-holding frame, of the rods passing through the same,the brush carried thereby, the spindle entering said frame, the bridge connecting said rods, and the spring on said spindle between said bridge and the head of said spindle, substantially as set forth.

6. An end-on commutator-brush adapted to rock in either direction and having a slot in the direction of its width, substantially as set forth.

This specification signed and witnessed this 6th day of December, 1886.

FRANK .T. SPRAGUE.

Witnesses:

I. F. S. BRAUTH, O. N. DEVER. 

